Apparatus for gunfire control



April 9, 1947. R. E. CROOKE APPARATUS FOR GUN FIRE CONTROL Filed Sept.22, 1955 I Q v2 3 wmwm INVENTOR Wm. Z'

' ATT NEY M m M W UM Patented Apr. 29, 1947 Raymond E Crooke, New York,N. Y., assignor to Ford Instrument Company, Inc., Long Island City, N.Yga' corp'oration ot'New York A a n ept mbe 22, 31 Ser a 519: atest '1invention relates to a method of and ap paratusrcrcondonin the firing?creme-ante arid iiarticmahy, to the determination "and an" plicationtothe ordnance ofcrtain cditrtiohl factors required foraccurafelyaiming'ifl The invention is whammy adapted for use in systemsin"which uliso'rj the "Iike'are coll? trolled from" an "instrument knovmc'or'npre' hensively as a director which measures the'p'resent'ldos'itio ri' of the target in train and elevation uch 1'1 irferredtd{1 un train andfi 'l coilfected g ln ele-- venom surthe u we'relocatedattli. oi

'- a V l J is:

When the horizontal distance between the .11: rector and a gun, usuallycalled thehase line; is appreciable it is necessary to add a horizontalparallax correction to the uncorrected gun train; In the case ofordnance being usedagainst aerial targets it is necessary in addition tothe parallax ir ec n n t am t aptl a Pa a l 'e e-i io' i in e ati n dueto the hori n al base ne as the line between the director and the'targetn he-11 e ween th gun in the ta 61 91 b th e in a o zqn a lane as the dij i the case of surface targets.

If, a'd ec or a a p a it of nd v dual uns are located substantially on'a straight linebut w h the uns at i erent di anc sfmmthe s r t dlli e dre or Q e PlefQ 2 121 boa d; the paral a corre ion quired t rtfi jet wh. t e,

ployed. In one of these systems the i tio'ns aredetermined' at" th 2? Cims: 5954 te fdance w th he pa t c lar val f t e ase line f'or"ts gunofbe'ihg socons'tructedthat-it v lue v V ,7 order 7 computinginstruments may, beintei "d'if necessary. The parallax corrections aftheguns by suitable"mchahimfin .7 Purpose." The chief disadvantages ofsystems of thils'jcharacte r arise from the tact that as manparallaxhomputing instruments are necessarvas there are guns; whichincreases theconiplerkitt and expense of the equipment required at eachgum I ..n In the other system, there i provided for each gun a singletransmitteiifor a pair of coarse and fine transmitters for sending, fromthe director to the gun, indications'ofthe'train required to be given tothe gun. A similar set of transmitters is provided for sending to thegun indicationsof the required elevation; Means are 'provided by whichthe operation of each transmitter is momfie'd in accordance withthe'base line of the gun controlled loj the' transmitter;- In this systemthere must be as many sets of train and elevation transmitters as thereare guns to be" controlled from the director. The complexity'and'experise of installations of this character constitute one of theirfihie fdis'advaintage's which are enhanced when pairs of coarse and finetransmitters are em'moyeug. as is usuallythe' case in present-day firecontrol equipment? Irisaccormnhyan object of the present invention toovercome the'di'sadvantages'of'prior sys ems for" applying a parallaxcorrection 'to' a piuralit yo't f orbhth" surface and aerial taiigtsiI"- general 'themethod consists in determining; 'with respect to a mainreference point, such as a director, the value of the parallax cor:rection for a, secondaryre'ference point, which may be one of the guns,and transmitting 1 r c ion t e" wa where e b n an, it is modified ateach gun in accordance Wlth the'ratioofthe baseline of the particu' rtermined are" introduced into"the"in d if- 3 reference point and whichis provided with means for transmitting the parallax correction to thegun. At each gun devices are provided for modifying the parallaxcorrection in accordance with the ratio of the base line of theparticular gun to the base line of the secondary reference point forwhich the parallax correction has been computed. The guns are alsoprovided with suitable receivers for receiving the indications ofuncorrected gun train and elevation transmitted from the director andwith means for combining with these indications the modified parallaxcorrections, in order that the guns may be correctly trained andpointed.

The particular nature of the invention, as well as other objects andadvantages thereof, will I appear most clearly from a description of aparticular embodiment as illustrated in the simplified drawing in whichD indicates in general a director including a computor C for determiningthe unit parallax corrections to be transmitted to gun units GA and GB.

Preliminary to describing the apparatus in detail, it will be explainedthat the parallax computor is intended to solve the following equa sin TIn these equations PT represents the parallax correction in train duevto a horizontal base line which may be regarded as unity. Therefore thebase line does not-appear as a term of the equation;

PE represents the parallax correction in elevation' due to the samehorizontal base line;

vEz represents the predicted elevated of the target; v

T2 represents the predicted train of the target;

R2 represents the predicted range of the target; K1, K2 are constantsdue to trigonometric approximations used in the equations.

--Assuming that the parallax correction has been determined for ahorizontal base line A, the relation between the parallax correction intrain due to a horizontal base line B, designated PTB, and that due tothe horizontal base line A, designated PTA, may be expressed as follows:

( P Base line B P Base line A Similarly the relation between theparallax correction in elevation due to the horizontal base line B,designated PEB, and that due to the .hori-- zontal base line A,designated PEA, may be expressed as follows:

is a bevel gear 1 engaging a bevel gear 8 on the end of a shaft 9supported in the standard 4 and carrying at its lower end a pinion l0engaging the rack 2. A compound gear I I has a bevel gear meshing withbevel gear I and a spur gear meshing with a gear attached to the side IQof a differential l2. The other side l2" of the differential is providedwith a gear meshing with a gear 13 attached to the end of a crank 54 bywhich correctional factors, other than parallax, may be introduced intothe values of train transmitted from the director to the gun. Inpractice the crank will be provided with an indicator to guide theoperator in properly adjusting the crank for particular values of thefactors.

The center IZ' of the difierential is connected through a train of gearsI5 to a shaft l6 which is attached to the rotor of a coarse transmitterFL The shaft I6 is connected by a train of gears Hi to a shaft Hi towhich is attached the rotor of a fine transmitter 2!]. Thesetransmitters send to the guns over conductors 2|, which for simplicityare shown as a single line, indications of the corrected train requiredto be given to the guns for properly aiming the latter, excepting forthe parallax correction, as will be hereinafter described.

Attached to the table 3 is a standard 22 carryinga shaft 23 to which areattached handwheels 24 to be used by the pointer of the director.Attached to the shaft 23 is a bevel gear 25 meshing with the bevel gearof a compound gear 26 the spur gear of which meshes with a gear attachedto the side 27 of a differential 21. The other side, 21'', of thedifferential is provided with a gear which meshes with a gear 28attached to the end of a crank 29 by which correctional fac-. tors,other than parallax, may be introduced into the values of elevationtransmitted from the director to the gun. As is the case of crank I4,

this crank will in practice he provided with a suitable indicator.

The center 21' of the differential is connectedthrough a train of gears30 to a shaft 3| to which is attached the rotor of a coarse transmitter32. The shaft 3| is connected by a train of gears 33 to a shaft 34 towhich is attached the rotor of a fine transmitter 35. Suitableconductcrs 36, shown conventionally as a,

single line, lead from the coarse and fine transmitters to transmit tothe guns indications of the corrected elevation required to be given tothe guns for properly aiming the latter excepting for the parallaxcorrection, as will be hereinafter described.

From the spur gear of the compound gear 26 a.

train of gears 3'! drives a shaft 38 which, through a pair of gears 39,shaft 40 and pair of gears 4|,

drives a worm 42 co-acting with a'gear sector'43. on a shaft 44rotatably mounted in a standard; 45 which will be understood to beattached to the tablet of the director. The shaft 44 carries,

to be described, are also mounted on the table. by

suitable supports which for simplicity have been omitted from thedrawing. 1

A crank 48 is adapted to be turned in accord 7 most of the devicesassociated with them are identical in the two units, correspondingelements in the units will be designated by the same referencecharacters, an exception being made in the case of those elements whichdiffer from each other in the two units.

Each unit includes a gun 9I mounted by trunnions in standards on aturntable 92 in the usual manner. The gun is adapted to be trained byhandwheels 93 on a shaft 94 which, through bevel ears 95, drives a shaft96 mounted in a standard on the turntable and provided with a pinion 91meshing with a fixed annular rack 97' surrounding the turntable of thegun. The gun is provided with an elevating rack 98 engaging a pinion ona shaft 99 which, through a gear train I09, is connected'to a shaft IIlIcarrying handwheels I02 by which the gun may be elevated in the usualmanner. The elements above described are shown in more or lessdiagrammatic manner, it being understood that they as Well as theelements about to be described will be arranged to move with the gun asit is trained.

The conductors from the coarse and fine train transmitters I7 and 20respectively, shown collectively as a single line 2i, lead to the rotorsof coarse and fine receivers I03 and I84 respectively, at the guns,these receivers being shown as of the zero-reading type with rotatablestators and each rotor shaft carrying a dial Hi5 provided with an indexadapted to be read against a fixed index I06. Driven from the shaft 96of the training gear of the gun is a shaft I'I carrying a bevel gear I08 which meshes with a corresponding gear formed on the side I99 of adifferential I09. The center I09' of the diiferential is connected by ashaft H0, bevel gears I I I, shaft H2 and gear train II3 to therotatable stator II4 of the coarse receiver I03. The shaft III) is alsoconnected by a gear train I I5 to the rotatable stator I I6 of the finereceiver I34. It will be understood that the ratio of the speeds atwhich the coarse and fine stators are driven from the shaft I I0corresponds to the ratio of the speeds between the rotors of the coarseand fine transmitters I I and 20 respectively, as is the usual practicein transmission systems of the character illustrated herein.

The conductors from the PT transmitter 89, indicated collectively by thesingle line 99, lead to the rotor of a zero-reading receiver N1, therotor of which carries a dial II8 having an index adapted to be readagainst a fixed index H9. The rotatable stator of the receiver II! isadapted to be turned by a crank I20 and a pinion I2I. In unit GA thecrank I29 also drives through a pair of bevel gears I22 a spur gear I23which ongages another spur gear I24 on a shaft I25 which is connected bya bevel gear I26 to the side I09 of the differential I09.

At this point it may be explained that the gun unit GA is the one forwhich the parallax corrections in train and elevation generated in theparallax computor of the director are suitable for application withoutmodification. Theparallax correction in train applied at this gun may,therefore, be regarded as one of the unit parallax corrections referredto in the introduction. The fact that this unit parallax correction isapplied to the gun unit GA without modification is indicated by thegears I23 and I24 being shown of the same diameter, whereas in the gununit G1; the corresponding gears I23 and I24 are shown in a 1:2 ratiosince the base line B is one-half the length of the base line A.

. The conductors indicated by'36 leading from the coarse and fineelevation transmitters 32 and 35, respectively, are connected to therotors of zero-reading coarse and-fine receivers I 21 and I28,respectively, each receiver having a rotatable stator and its rotorbeing provided with a dial I29 having an index adapted to be readagainst a fixed index I 30. The shaft 99 of the gun elevating mechanismis connected by a bevel gear I 3! to a corresponding gear formed on theside I32 of a differential I32. The center I32'" of the difierential isconnected by shaft I33 and pinion I34 to the rotatable stator of thecoarse receiver I21. This shaft is also connected through gear train I35to shaft I35 and gear train I37 to the rotatable stator of the finereceiver 28, the speed ratio between the stators of the coarse and finereceivers being the same as the speed ratio between the rotors of thecoarse and fine transmitters 32 and 35, respectively.

The conductors indicated by I6 leading from the PE transmitter I5 go toa zero-reading receiver I38, the rotor of which is provided with a dialI39 having an index reading against a fixed index I49. The stator ofthis transmitter is adapted to be turned by a crank MI and pinion I42.In unit GA the crank I 4| also drives through a pair of bevel gears I43,shaft I44, gear I45, gear I and bevel gear I41 a corresponding bevelgear formed on the side I32" of the differential I32.

As explained above in connection with the parallax correction in train,the parallax correction in elevation which is applied to the gun unit GAmay be regarded as the unit parallax correction since it requires nomodification. This is indicated by the fact that the gears I45 and I46of this unit are of the same diameter, While the corresponding gears I45and I46 of gun unit GB have a 1:2 ratio on account of the similar ratioof the base line B to the base line A.

In the operation of the apparatus described above, the trainer keeps histelescope 41 on the target by suitable manipulation of his handwheels 5which through shaft 5, gears 'I and 8, shaft 9 and pinion I I] willcause the table 3 to be turned within the fixed annular rack 2. At thesame time the handwheels will, through gear 'I and compound gear II,drive the side I2 of differential I2. The side I2" will be driven inaccordance with the correctional factors which are continuously or fromtime to time introduced by manipulation of crank I4. The movementsimparted to the sides of the differential are combined at its center I2"and from it imparted to the rotors of the coarse and fine transmittersIT and 20, respectively.

The movements of these rotors will be reproduced in the coarse and finereceivers H33 and I04, respectively, at the guns to correspondinglydisplace the indexes on the dials I 05 with respect to the fixed indexesI06. The trainers at the guns will turn their handwheels 93 which,through shafts 94, bevel gears 95, shafts'95 and pinions 91, will rotatethe turntables 92 on which the guns are mounted. At the same time,through shafts H11 and bevel gears I38, the sides I39 of thedifferentials I99, will be correspondingly rotated. Assuming for thetime being that the cranks I20 are stationary, the sides I09" of thedifierentials' will be stationary so that the movements imparted by thehandwheels will be transmitted from the centers IIl'Sf" of thedifferentials through shafts I I0, gears I I l, shafts I I2 and geartrains II3and II5 to the stators H4 and IIS of the train receivers I93and I04, respectively. The

and eIeVating racks -98.

trainers will rotate ltheir 'han'dwh'eels until the lindexeson thedialsof the receivers have been restoredto coincidence with the fixedindexes I08 to indicate to the trainers that the guns have been trainedin accordance with the information transmitted from the director, in amanner well *known in transmission systems of the type employed herein.

Simultaneously with the operationof the training mechanism describedabove, the pointer at the director will, if the system is being operatedfor continuous aim, manipulate his handwheels 24 to maintain histelescope 40 on the target in elevation, through shaft '23, gear .25,:compound 'gear '26, gear train 31, shaft 30,gears '39, shaft 40,,gears4|, worm 42 andgearsector43 attached to the shaft 44 on which thetelescope is mounted. #At' the same time the compound gear 26 :willdrive the side 2'! of differential 21 and corrections in elevation willbe applied'by manipulation of crank 29t0 correspondinglyposition theside "21" of the diflerential bygear 28 on the crank. The movementsimparted to the'sides of the differential will be combined at its center*2? and through gear train'30 and shaft 3| the rotor of the coarsetransmitter32 will be accordingly turned and through gear train 33 andshaft 34 the rotor of fine transmitter 35 willbe'turne'd. The resultingmovements of theserotors will be transmitted over conductors 36 to thecoarseand fine receivers I2! and I28, respectively, at the guns to causecorresponding displacements of the indexes on dials I29with respect tothe fixed indexes I30.

The pointers at the guns will manipulate their through shafts IIII, geartrains I00, shafts 90 Simultaneously the shafts 99 will, through gears II3 I drive the sides I32 of diiferentials I32. Assuming thatthe cranksI4I are stationary, the other sides I32" of the differentials will bestationaryso that the movements of the-sides I32 will beimparted-to thecenters 132" and to shafts I33 andpinions I34 to correspondingly turnthe stators-of the coarse receivers I21. At the same time the stators ofthe line receivers I28 will be driven from the shafts I33 through geartrains I35, shafts I36 and gear trains I31. The pointers will-continueto rotate their handwheels until the indexes on the dials I29 havebeenrestored to coincidence with the-fixed indexes I30 indicatingthatthe guns have been elevated in-accordance with the'data sent fromthe director.

"While the trainer-and pointerof the director are operatingtheirchains'of mechanism toenable the trainers and pointers atthe-guns-to prope'rly aim theguns in accordance with the required trainand elevation of the target, I correctedfor factors other thanparallaxother operators will be introducing inputs of predictedelevation Ez, predicted train Tz and predicted range R2 by manipulationf*cranks-60, 48 and 54, respectively, to actuate theassociatedmechanisms of the parallax computor' C as previouslyexplained. "Thefinalresult of these operations willbe tozimpart-to therotor of theztransmitter 80 a" movement in'accordance with the requiredparallax correction intrainwhich will be'transmitted over conductors 90to the parallax receivers Ill. at the guns .to correspondinglydisplacetheirrotors and theindexes on their dials H8 withrespect to the fixedindexes. I I9. At thesame time the;cranks "I20mwill be turned byoperators who observe the'dials H8 and restore the indexes 1.0 thereon-.to coincidence with the fixed indexes :I I9 by .rotation of thestators of thereceivers by the pinions I2I on the.cranks;l20.

The :movement imparted to .the \crank I20 :of gun unitGAwillthroughgears I22, I23, ';I24, shaft 4 25 and gear I26 correspondinglyturn the side 4 09" of differential 100, -to impart to the :center 409""of the differential -a movement corresponding to "the required iparallaxcorrection in (train in addition to themovement imparted to it fromtheside :I00 ofithe difierential as described-above. The additionalmovement of the center of ithe .-.difierentia1 due to the parallaxcorrection applied tolit will superimpose upon-the movementorigiinallyimpartedtothe stators-of the train receiviers I 03 and II 04anadditional displacement which mustbe'taken into account by the traineras-he turnsrhis it gun to place the indexes-on the dials I05 incoincidence with the fixed indexes I06. iWhen-this has :been done therequired parallax "correction will have been applied to gun 9| of unitGA, .vvhich, as-exp1ained above, is the unit for which-the parallaxcorrection generated-by the-parallaxcomputor has unitvalue.

since the parallax correction generated at the director is transmittedwithout modification' to the parallax-receiver -I I! at thegun unit Geto correspondinglydisplace its dial IIB, it-is necessary to modify thiscorrection at this unit before it is appliedtothegun. As'in the caseof'the unit GA,-' the crank-I 2-0'ofthe unit G13 will bemanipulated-toturn its pinion I2I and the stator of the-receiver untilthe index onthe dial-is brought into; coincidence with the fixed index II9; but the movement imparted to-the side I09 of the-diiferentialIIlBofthis-unitwill be reduced by the ratio of gears I23 and I24, inproportionto the relation xbetween the base line B and baseline .A aspreviously described. The subsequent 015- erationsperformedby the-guntrainer of unit GB iwill be like those-described in connection withunit"Ga so that ultimately the required parallax correction in trainwill beimparted to the gun =9I of-unit GB.

As previously described, the rotor ofthe transmitter IB-at the directorwill be turned in accordance :with. the required parallax correction inelevation which will be reproduced-in therottors andidials I39 of thereceivers I38 of theguns. The indexes on the-dialswill be restored tocoincidence withthafixed indexes I40 by rotating the stators of v thereceivers by manipulation" of the cranks-l4l and pinionsl'42. In thecase of" gun unit"GA=the-movement of crank I4I Iwi1l came through bevelgears I43, shaft I44, gears I45, I46 and I41, a corresponding movementof the side- I32" of differential I32.- The-movement transmitted fromthe crank I4l to the side-I32" will be -in' l:'1- ratio as described inconnection with the parallax correction in train and for-the samereason.

In gun unit GB,- on the other hand, the transmission from the-crank I4Ito the side I32"flof ,the differentiaLwill-be in al z2 ratio on accountof the-lesserbase-lineof this unit,;this ratio-being obtained bysuitable proportioning of the gears 1-45 and MEof this-unit.

In both units,= however, the result of .the'application of -the parallaxcorrection in elevation will be to cause through the movements of thecenters 132" of thediffierentials I32,shaf,ts, I33 andthe gears bywhiclrthey are connected to the stators of the elevationreceivers I2],I28, an additional-displacement of the'rotors and dials orthese--receivers, these additional displacements anassc beingcompensated for by the pointers at the guns imparting additionalmovements to the guns by operation of their handwheels in a mannersimilar to that described in connection with the application of theparallax correction in train.

Since the device for modifying the parallax corrections received at thedifferent gun units include gear trains having diiferent ratios, theunits may be interchangeably arranged with respect to the director bythe selection of suitable gear ratios in accordance with the base linesof the units.

While a preferred embodiment of the invention has been shown anddescribed, it will be understood that the invention may be embodied inother forms and that various changes may be made in structural detailswithout departing from its principles as defined in the appended claims.

I claim:

1. In a fire control system, the combination of a plurality of guns,means for determining values of a correctional factor for one of theguns comprising elements adjustable in accordance with the futureposition of a movable target, means for transmitting the values of thefactor to that gun and to the remaining guns, and means at each of saidremaining guns for converting the values transmitted thereto to theparticular values of the factor required for that gun.

2. In a fire control system, the combination of a plurality of guns,means operable in accordance with the anticipated future position of atarget, for determining values of a correctional factor for adjustingthe aim of one of the guns, means for transmitting the values of thefactor to that gun and to the remaining guns, and means at each of saidremaining guns for converting the values transmitted thereto to theparticular values of the factor required for that gun, each of said lastnamed means including coacting elements having a motion transmittingratio depending upon the particular conversion which the means effects.

3. In a fire control system, the combination of a plurality of guns,means operable in part in accordance with predicted train and elevationof a movable target for determining values of correctional factors forone of the guns, means for transmitting the values of the factors tothat gun and to the remaining guns, means at each of the guns forreceiving the transmitted values for directing the aim of the guns, andmeans associated with the receiving means at each of the remaining gunsfor converting the values of the factors received thereat to the valuesrequired for that gun.

4. In a fire control system, the combination of a plurality of guns,means operable in accordance with predicted train, elevation and rangeof a movable target for determining values of correctional factors forone of the guns, means for transmitting the values of the factors tothat gun and to the remaining guns, means at each of the guns forreceiving the transmitted values, means associated with the receivingmeans at each of the remaining guns for converting the values of thefactors received thereat to the values required for that gun and meansassociated with the last named means for directing the aim of the gun.

5. In a fire control system, the combination of a plurality of gunsrequiring different values of a correctional factor for their aiming,means for determining an arbitrary value of the factor, a transmittingdevice common to all the guns and operable by the determining means fortransmit:- ting the arbitrary value of the factor to the guns, means ateach of the guns for receiving the transmitted value for directing theaim of the gun, and means associated with each receiving means operablein accordance with the arbitrary value of the factor received thereatincluding means for converting said arbitrary value to the particularvalue required for that gun.

6. In a fire control system, the combination of a plurality of gunsrequiring different values of a correctional factor for their aiming atan antici pated future position of a target, means operable inaccordance with quantities dependent upon the future position of thetarget for determining the valeu of the factor for one of the guns,means for transmitting the determined value to that gun and to theremaining guns, means at each of the guns for receiving the transmittedvalue and means associated with the receiving means at each of the,remaining guns for converting the value of the factor received thereatto the value required for that gun.

7. In a fire control system, the combination of a plurality of gunsrequiring different values of a correctional factor for their aiming,means for determining an arbitrary value of the factor, a transmittingdevice common to all the guns and operable by the determining means fortransmitting the arbitrary value of the factor to the guns and means ateach of the guns operable in accordance with the arbitrary value of thefactor received thereat and including means for converting saidarbitrary value to the particular value required for that gun.

8. In a fire control system, the combination of a plurality of gunsrequiring different values of parallax correction for their aiming,means for determining an arbitrary value of the parallax correction, atransmitting device common to all the guns and operable by thedetermining means for transmitting the arbitrary value of the parallaxcorrection to the guns and means at each of the guns operable inaccordance with the arbitrary value of the parallax correction receivedthereat and including means for converting said arbitrary value to theparticular value required for that gun.

9. In a fire control system, the combination of a plurality of guns eachrequiring different values of correctional factors affecting the aimingthereof, means for determining values of the correctional factors for aparticular gun, a transmitting device common to all the guns andoperable by the determining means for transmitting the values of thefactors to the particular gun and the remaining guns, means at theparticular gun for applying thereto the determined values of thecorrectional factors and means at each of the remaining guns forapplying thereto the determined values of the correctional factorsmodified in accordance with the particular values required for the gun.

10. In a fire control system, the combination of a plurality of gunslocated at different distances from a reference point, mechanism fordetermining the parallex correction with respect to the reference pointfor a particular gun, means for transmitting the parallax correction tothe particular gun and the remaining guns, means at the particular gunfor applying thereto the parallax correction and means at each of theremaining guns for applying thereto the parallax correction modified inaccordance with the distance of the gun from the reference point.

reference point'for a particular gun, meansfor transmitting the parallaxcorrection to theparfjticularlgun'an d to the remainingguns, and means,forl m difyingthe parallax correction as received fatjsaid remainingguns inaccordance with the different distances of the'guns from thereference 'q n -H 12, Ina firecontrol system, the combinationjof"afdirectingdevice, a Dl'uralitycf guns located atdiiferentfdistances from the device means at the device for,dete'rminingthe"parallax correcti'cn for a particular gun, means at thedevice for transmitting the parallax correction to the particulargunan'd t'othe "remaining guns, and meansateach of saidremaining gunsfor modifying the parallax correctionreceived thereat in accordance withthe distance of the gun from the directing device.

13 m a fire control system, the combination ,of ajiplurality of gunsrequiring for their aiming ,acoinmcn valueof "a main factor anddifferent j i r'idiv idual values'of a correctional factorgmeans :ffortransmitting thecommon value to all of the jjguns, means at each gunfor' receiving'the transmittedyalues of the common factor, meansfordetermining the value of the correctional factor for one of the guns,means for transmitting the determined value of the correctional factorto that gun and to the remaining guns, means at each gun for receivingthe transmitted value of the correctional factor, means associated withboth receiving means at each remaining gun for converting the value ofthe correctional factor received thereat to the value required for thatgun, and means under the control of both receiving means and theconverting means at each gun for directing the aim of the gun.

14. In a fire control system, the combination of a directing device, aplurality of guns requiring for their aiming a common value of a mainfactor and different individual values of a correctional factor, meansunder the control of the directing device for transmitting the commonvalue to all of the guns, means at each gun for receiving thetransmitted value of the common factor, means for determining the valueof the correctional factor for one of the guns, means for transmittingthe determined value of the correctional factor to that gun and to theremaining guns, means at each gun for receiving the transmitted value ofthe correctional factor and means associated with both receiving meansat each remaining gun for converting the value of the correctionalfactor received there-at to the value required for that gun.

15. In a fire control system, the combination of a plurality of guns,means for determining values of a correctional factor for a referencepoint, means for transmitting the values of the factor to each of theguns and means at each of the guns for converting the values of thefactor transmitted thereto to the particular values of the factorrequired for that gun in accordance with its relation to the referencepoint.

16. In a fire control system, the combination of a plurality of gunslocated at different distances from a main reference point, means fordetermining values of a correctional factor for a secondary referencepoint, means for transmitting the values of the factor to each of theguns and means at each of the guns for converting *th in ect? ne meratenga e 'guired for 1 that gun in accordance with-it's relation tothesecondary reference point.

time 5f endant cadres-teamed it. in a fire control system, the coinbinationf of a directing device, a plurality of guns requiringfgrtheir'aiming common main values of train "and jiiff'erent individualvalues of a correctional factor of train, means under the control of thedirecting device for transmitting the common main values to all ofthe'guns, means at'each gun for receiving the transmitted common'mainvalues, means for determining arbitrary values of the correctionalfactor of train,a transmitting device common to all 'the' guns andoperable -by the' determining means for transmitting the 'de- -tlerrnined-arbitrary values of the correctional fac- Vtori to each of theguns, means at each gun for receiving the transmitted arbitrary valuesof the correctional facton means associated with} each gunjformonverting the arbitrary values of the correctional factoryreceivedat the gun 'to* the value required-forthatgun,and means at each i'gu'nunder the control of 199th said receiving meansat 'the'gun for directingthe *a'im of the un.

18. In affiie l-control system, thecofnbiriation rl a d re i azeev fee"p uia w of n ir qt ing fortheir aiming common main values of(alevation and different individual values of a correctional factor ofelevation, means under the control of the directing device fortransmitting the common main values to all of the guns, means at eachgun for receiving the transmitted common main values, means fordetermining arbitrary values of the correctional factor of elevation, atransmitting device common t9 all the guns and operable by thedetermining means for transmitting the determined arbitrary values ofthe correctional factor to each of the guns, means at each gun forreceiving the transmitted arbitrary values of the correctional factor,means associated with each gun for converting the arbitrary values ofthe correctional factor received at the gun to the value required forthat gun, and means at each gun under the control of both said receivingmeans at the gun for directing the aim of the gun.

19. In a fire control system, the combination of a directing device, aplurality of guns requiring for their aiming common main values of trainand elevation and different individual values of a correctional factorof train and elevation, means under the control of the directing devicefor transmitting the common main values to all of the guns, means ateach gun for receiving the transmitted common main values, means fordetermining arbitrary values of the correctional factor of train andelevation, a transmitting device common to all the guns and operable bythe determining means for transmitting the determined arbitrary valuesof the correctional factor to each of the guns, means at each gun forreceiving the transmitted arbitrary values of the correctional factor,means associated with each gun for converting the arbitrary values ofthe correctional factor received at the gun to the value required forthat gun, and means at each gun under the control of both said receivingmeans at the gun for directing the aim of the gun.

20. In a fire control system, the combination of a directing device, aplurality of guns located at difierent distances from the device, meansat the device for determining values of a correcaynasse 15 tional factorfor a reference point, means at the device for transmitting the valuesof the factor to each of the guns and means at each of the guns formodifying the values of the correctional factors received thereat inaccordance with the relation of the gun to the reference point.

21. In a fire control system, the combination of a plurality of guns,means for determining a value of a correctional factor required for theaiming of one of the guns, a transmitting device common to all the gunsand -operable by the determining means for transmitting to said one ofthe guns and to the remaining guns the determined value of thecorrectional factor, means at each of the guns for receiving thetransmitted value of the correctional factor and means associated withthe receiving means at ,each of the remaining guns for converting thereceived value of the correctional factor to the particular value of thefactor required for that gun.

22. In a fire control system, the combination of a plurality of gunseach requiring for its aiming a value of a correctional factor differingfrom the values required for the other guns, means for determining anarbitrary value of the factor, a transmitting device common to all theguns and operable by the determining means for transmitting to the gunsthe arbitrary value of the factor, means at the guns jointly responsiveto the transmitting device for receiving the arbitrary value of thefactor and means associated with the receiving means at each of the gunsfor converting the arbitrary value of the factor to the particular valueof the factor required for that gun.

23. The combination with a plurality of guns, of means for determining acorrection factor for laying one of said guns, means for transmittingsaid factor to each gun of said plurality of guns, and mechanical meansincluding gear trains having different ratios associated with each gunto apply said factor to the respective guns, the said ratios beingproportionate to the distance of the respective gun from a referencepoint.

RAYMOND E. CROOKE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,692,364 Akemann Nov. 20, 19281,172,979 Giradelli Feb. 22, 1916 1,894,822 Hewlett et a1 Jan. 17, 19331,557,702 Kaminski Oct. 20, 1925 1,695,483 Dawson et a1 Dec. 18, 1928

